With the ever increasing desire for faster data rates, notably through long-term evolution-Advanced (LTE-A) networks in Release 10, system designers have turned several different techniques such as multiple input multiple output (MIMO), cooperative multiple point transmission (CoMP) and carrier aggregation. Carrier aggregation increases bandwidth, and thus bitrate, by aggregating multiple carriers to form a larger overall transmission bandwidth. Carrier aggregation, until recently, has been limited by 3GPP specification to aggregating five carriers. The number of carriers able to be aggregated has increased to thirty two in 3GPP Release 13 to effect enhanced carrier aggregation. However, the increase in the number of carriers concomitantly linearly increases the number of blind decoding attempts of the user equipment (UE) (all possible combination of physical downlink control channel (PDCCH) and enhanced PDCCH (EPDCCH) locations and formats, and DCI formats) to decode control information transmitted by the enhanced Node-B (eNB). Moreover, one solution to the explosive increase in mobile data consumption has been to deploy LTE in the unlicensed spectrum (LTE-Unlicensed (LTE-U), with UEs using the LTE-U band referred to as License Assisted Access (LAA) UEs). Unfortunately, carrier use on the unlicensed spectrum is opportunistic due to coexistence with and use of other deployed wireless devices, such as WiFi and Bluetooth, on the unlicensed spectrum. The opportunistic nature of the unlicensed spectrum may limit transmission and reception of the control (and corresponding data) signals on the unlicensed spectrum, thereby reducing the bitrate. The increase in the number of carriers, as well as the bands in which the carriers reside, may result in a significant increase in blind decoding attempts, which causes a decrease in the bitrate as well as an increase in the complexity and power consumption of the UE.
It would be therefore desirable to enable enhanced carrier aggregation for UEs without decreasing the bitrate.